The invention here is a kind of improved structure pump valve for concrete mixture pumping trucks, and in particular a kind that has a pump valve structure that is easily replaced and long lasting.
With the gradual development of modern engineering, as construction involves excessive height, length, area, distance and sheer scale area, special tools are overcoming the difficulties of building. In this kind of construction, it is difficult to avoid the use of various pumps to build contiguous walls, ground foundations or skirts and bridge columns and so on. Human labor is incapable of meeting the requirements of this type of construction and has been replaced by a kind of concrete pumping truck, which is a specialized truck having a kind of flexible pipe and a rear hopper, wherein a pump conveys the concrete mixture at high pressure through piping, and then delivers it from the rear end of the piping to the desired construction site, the piping being similar to a fire fighting ladder truck in that it can be lengthened to higher, deeper or farther areas for effortlessly conveyance of the concrete mixture rapidly to each area. In the present age of labor shortages and inflated labor wages, this equipment is not only a kind that saves human labor and lowers cost but, furthermore, shortens construction periods and raises economic efficiency.
This kind of concrete pumping truck, whose building principles are indicated in FIG. 1 and FIG. 2, makes use of the pump delivery valve structure of currently utilized concrete pumping trucks, which after the concrete mixture is conveyed from the hopper (H), and extracted from two pistons (P) and the S-bend pipe (S) of a exchanger valve, conveys the concrete mixture out at high pressure through the piping (A). The S-bend pipe (S) uses a crank tip (R) at one end that is subjected to a gas cylinder (C) at the lower end to produce the movement of the operation which, when conjoined to the surface of the S-bend pipe (S) is capable of conveying the concrete mixture. The other opening momentarily suctions in the concrete mixture such that when the S-bend pipe (S) once again moves to the opening that just suctioned in the concrete mixture, the piston (P) then conveys the concrete mixture out. As a result, the concrete mixture passing through this kind of S-bend pipe (S) can be conveyed out at high pressure from the valve cut-off of the valve (V). An alternative kind of pump structure, as indicated in FIG. 3 and FIG. 4, consists of a sliding rod (d) attached at the top to a shut-off plate (d1) and, furthermore, utilizes the aforesaid sliding rod (d) for insertion into the two valves (V), utilizing the oil pressure cylinders (O) at the front and the rear end of the sliding rod (d) to produce reciprocation that causes the shut-off plate (d1) to move back and forth between the two valves (V) and remain aligned with the reciprocal motion of the two pistons (P) to achieve the conveying of the concrete mixture at high pressure out through the pipe (A). Since the pump valve structure is the heart of the main power resource of the concrete pumping truck pump that conveys the concrete mixture to the work site main force, the overall capability of the concrete pumping truck to convey the concrete mixture is involved and, therefore, no matter whether use is made of the aforesaid S-bend shut-off pump valve or, as indicated in FIG. 3 and FIG. 4, the flat cut plate-type shut-off valve structure, the shut-off component (the S-bend pipe or the sliding rod), must have a very rapid reciprocating speed and, furthermore, must have a high degree of friction-resistance and impact resistance. The problem is that, as acknowledged, for a majority of metal materials, friction-resistance and impact-resistance normally exist in inverse proportions. Thus, in the case of pump valves, while the aforementioned conventional S-shaped pipe shut-off valve structure has a usable frictional wear service life of 12,000 cubic meters to 15,000 cubic meters., which is longer than the frictional wear service life of flat cut plate-type pump valves, fabrication of the valves is difficult in that the friction-resistance is not fully ideal and the valve cannot be adjusted after frictional wear occurs due to the clearances between the S-bend pipe and the other two components, and the price of fabrication is high, among other related shortcomings. On the other hand, in the case of the flat cut plate-type pump valve structure, mostly due to its structural shape, in actual utilization tests, after high speed sliding shut-off friction and concrete mixture impacts of between approximately 8,000 cubic meters has occurred to 12,000 meters, not only do extremely large clearances (F) occur in between the two valves (V) and cut-off valve (d1), but also between the linkage of the sliding rod (d) and the sleeve of the valve (V), which produces fissures (f). In both cases, disassembly and reassembly is difficult, as indicated in FIG. 5, and therefore, pump valves that are not friction-resistant and that cannot be adjusted after frictional wear and other related shortcomings are rarely observed in present-day pumping trucks. Since the pump valve is not friction-resistant, excessively large clearances are produced between the valves and the shut-off components resulting in the phenomenon that, when the pump is conveying concrete mixture, the concrete mixture and the water content leaks through the aforesaid clearances and gives rise to hardening of concrete mixture, obstructing the concrete mixture delivery process. Since, when the concrete mixture is being conveyed, the concrete mixture and water content must be first stirred, if the water content and the concrete mixture leaks through the aforesaid clearances, the insufficient concrete mixture delivery pressure affects the high pressure value and high water level high pressure concrete mixture delivery which leads, as a result, to also causing the concrete mixture to harden and clog the piping and finally, the pump valves must be frequently replaced, leading not only to increases in component costs but, furthermore, to the expenditure of time and effort for the installation process, thereby extending the construction period. In view of this, the inventor of the invention herein has improved the structure of the conventional pump valve, utilizing a modular design and a simple component assembly resulting in a simplified pump valve structure, enabling the friction-resistance to meet actual requirements, which not only lowers manufacturing costs and significantly increases its usable frictional resistance, but also increases its usable service life and, furthermore, in terms of the simplified structure, is capable of achieving simple disassembly, easy fabrication. In addition, the S-bend pipe of the invention herein has an adjustment screw with fine adjustment capability, which significantly increases the usable service life and constitutes a major objective of the invention herein.
To achieve the aforementioned objectives, the technological means and functions utilized by the invention herein is presented as accompanied by the brief description of the drawings followed by the detailed description, to thereby enable a further understanding of the structure, innovative characteristics and functions of the invention herein.